Many thanks for your prompt reply. I was afraid your diagnosis might be the reply I would receive!
I am considering changing the oil to Amsoil 85W-140, which I know is a grade too heavy. Do you think it could damage the bearings?
The car runs in a fairly moderate climate. The temperature ranges from 2deg.C in the winter to, say, 33deg in the summer. And there is no sustained high speed touring.
Your opinion will be much appreciated.
Regards, Murray Blackwood.